1. Field of the Invention
The present invention relates to off-shore drilling equipment. More particularly, the present invention relates to a device for filtering the drilling mud and cuttings that are brought to the well head to be recirculated through a flow line.
2. General Background
During the drilling process and the production of off-shore oil and gas wells, cuttings and other debris from the drill bit down within the drill hole are brought up to the surface by means of pumping drilling mud under pressure down the drill pipe, into the drill hole, and circulating the mud along with the cuttings and other materials back to the surface through the exterior casing. Upon reaching the surface of the drilled hole, the mud, cuttings and other material are routed up the casing through the well head into a flow line which angularly allows the mud to flow away from the drilling site to be separated from the cuttings in separators and recirculated under pressure back down into the holes for use once more.
One of the most troublesome problems one confronts in this operation is the constant coagulation of mud and cuttings within the flow line and the ultimte blockage of the flow of mud and cuttings therethrough. When, in fact, the flow line becomes blocked, the flow of mud through this line is interupted. Therefore, the mud and materials, rather than routed through the flow line, are forced up to the surface, on the drill floor, which results often times in the loss of quantities of valuable drilling mud which is expensive and time consuming to replace and replenish. Also, the line must be unclogged which creates down time in the operation of the rig, consequently a loss of valuable revenues.
There is no apparatus which is being used by the off-shore industry, which is known to this inventor, which could prevent the coagulation of mud through the flow-line without interrupting the flow of mud therethrough.
Several apparatuses have been patented which attempt to serve as a filter for the cuttings from a well. They are as follows:
U.S. Pat. No. 3,880,762 issued to Roger Wise entitled "Separator for Cuttings" teaches a separator for drill bit cuttings being disposed on the top of a well pipe having a container surrounding the pipe in a slide area on the top of the container, the slide area being comprised of a plurality of spaced, elongated elements inclined downwardly from the top of the pipe sleeve. This particular patent addresses the problem of filtering out cuttings which may collect and clog the shaker screen. This particular apparatus would, in affect, have to have a filter screen which would filter cuttings of a very minute size so as not to clog the shale shaker screen and, for our purposes, would be ineffectual and inoperative.
U.S. Pat. No. 4,116,288 issued to William W. Love, entitled "Method and Apparatus for Continuously Separating Lost Circulating Material From Drilling Fluid" would teach the use of the method and apparatus for processing drilling mud. The lost circulating material is retained on a coarse screen while the mud and drilling solids pass through a finer mesh screen. This particular apparatus is a rather involved separator apparatus and would not suit the particular needs of this invention.
Other patents which are presently in the art are U.S. Pat. No. 3,774,702 issued to Wayland Elenburg entitled "Formation Chip Sampling Method," U.S. Pat. No. 2,169,675 issued to G. S. Bays entitled "Back Pressure Control in Pressure Drilling," U.S. Pat. No. 2,514,585 issued to M. L. Natland entitled "Method for Drilling Wells" and U.S. Pat. No. 2,870,990 issued to T. G. Bergey entitled "Drilling Fluid Method" are all directed toward cleaning drilling mud and recirculating it, but each of these particular apparatuses do not serve to meet the needs of this particular invention.